Proportional spacing mechanism



1957 F. w'. SCHREMP 0 PROPORTIdNAL SPACING MECHANISM Filed Sept. 13, 1955 I7 l8 l9 INVENTOR FREDERICK HREMP I B ATTORNEY United States Patent O 2,803,330 PROPORTIONAL SPACING MECHANISM Frederick W. Schremp, Stamford, Conn., assignor to Sperry Rand Corporation, New York, N. Y., a corporation of Delaware Application September 13, 1955, Serial No. 534,074 3 Claims. (Cl. 197-84) This invention relates to new and useful improvements in mechanism for effecting variable spacing in typewriters and like machines.

The object of this invention is to provide a simple, efficient, and relatively inexpensive mechanism whereby variable or proportional spacing is effected merely by the depression of the character keys.

The invention is described and shown in the drawings as applied to a Remington typewriter, more specifically known as a Model 17 or Remington Standar or Remington Electric. The typewriter mechanism with the exception of those parts illustrated in this application is substantially similar to the structure shown in Patent Nos. 2,289,531, July 14, 1942; 2,304,216, December 8, 1942; 2,326,312, August 10, 1943; 2,579,763, December 25, 1951; and 2,638,199, May 12, 1953; in view of which only those portions of a typewriter are illustrated as are necessary to show the invention in association with related typewriter parts.

In brief and general terms, the invention includes an escapement wheel and pinion rotatable on a shaft on which a series of spacing gears are also rotatably mounted. Each gear has a concentric slot which is of different lengt than the slots in the other gears. A rod fixed to the wheel extends through the slots. Stop pawls are asscoiated with the gears and the usual escapement pawl is associated with the escapement wheel. The escapement pawl and a selected stop pawl are simultaneously operated by the depression of a character key to release the wheel and stop a selected gear whereupon the wheel rotates until the rod thereon is halted by the end of the slot in that gear. In this manner the wheel turns a determined distance and therefore the carriage rack connected to the escapement wheel in the usual manner is allowed to space a desired distance. The difference in the lengths of the slots in the gears allows the spacing of the carriage to different distances depending upon the width of the characters it is desired to print.

A present preferred form which the invention may assume is illustrated in the drawings, of which,

Fig. 1 is a front elevation of the spacing mechanism; and,

Fig. 2 is an exploded isometric view of the mechanism.

Referring now merely to the specific form of the mechanism shown in the drawings, there is the usual escapement wheel 10, free on a shaft 11, to which wheel is fixed a pinion 12 meshing with the carriage rack bar 13. A spring, not shown, tends to move the rack bar 13 to the left as shown in Fig. 2. An escapement lever 14 is pivoted on an axis or shaft 15 and is operated by a link 16 connected thereto. A spring pressed pawl 14' on lever 14 is adapted normally to engage the teeth on the escapement wheel 1%.

Adjacent the wheel 16 there is a series of variable spacing gears nominated 17, 18, 19 and 20 the hubs of which are rotatable on the shaft 11. The teeth of these latter gears are adapted to be engaged by respective pivoted stop pawls 21, 22, 23, and 24 which are normally out of engagement with the teeth of these gears. Each of these ICC stop pawls is connected to respective links 25, 26, 27, and 28 The gears 17 to 20 inclusive are provided respectively with three concentric slots 29, 30, 31 and 32. These slots, from gear 17 to gear 20 are of increasing length as shown. Rods 33, of which there are three, are fixed at one end to the wheel 10 and extend through the slots in the gears 17 to 21 inclusive. Normally the rods lie in the right end of the slots and this normal position is achieved by means of springs 34 which at one end are fixed to the respective gears and at the other end to one of the rods 33 thus tending to pull the gears so that the right end of the slots will bear against the rods 33.

When the regular spacing bar (not shown) is operated the escapement lever 14 will disengage pawl 14' from the wheel 10 and at the same time the stop pawl 21 by mechanism (not shown) will be engaged with the gear 17 to cause the gear 10 to space two increments which is the smallest spacing distance. Now if a smaller letter or character such as an i or a dot is to be printed, its key is depressed and then the stop pawl 21, as shown in Fig. 2 will be moved to lie back of a tooth on the gear 17. This movement is effected by the usual linkages and permutation bars known in typewriter mechanisms. The slots 29 in the gear 17 are of such a circumferential length as to permit a movement of two increments. As the key mentioned is depressed, associated mechanism (not shown) will pivot the lever 14 and disengage the pawl 14 at which instant the spring previously referred to will cause the wheel 10 to rotate until the rods 33 thereon move to the left end of the slots in the gear 17 thus moving the wheel 10 and consequently the carriage two increments. It will be observed that as the rods 33 are thus moved counterclockwise the other gears not stopped by their pawls will be moved by the springs 34 to keep the right sides of their slots in contact with the rods 33.

When letters or characters of greater width are to be printed, then through the associated linkages and permutation bars, above mentioned, the proper stop pawl will be engaged with its gear and the rods will be permitted to move a greater distance. It will also be noted that when a stop pawl is released by removal of pressure on its associated key, the spring 34 on its related gear will instantly move the gear to bring the right end of the slots in abutment with the rods ready for the next imprint. It will also be borne in mind that when a character key is depressed, the pawl 14 is hetld out of engagement with the wheel 10 until the key is released in order to allow the spacing movement to be completed.

The slots in gear 17 are intended to be equal to the distance between two teeth of gear 10; in gear 18 equal to the distance between three teeth; in gear 19 equal to the distance between four teeth; and in gear 21? equal to the distance between five teeth. When the smallest increment is to be imparted to rack bar 13 in letter spacing direction, the pawl 21, as above stated, is rocked into engagement with the teeth of gear 17 at the same time that the pawl 14' is rocked out of mesh with the teeth of wheel 10. This permits the carriage drive spring (not shown) to draw the carriage and carriage rack 13 leftward until the rods 33 engage and are stopped by the left end of the slots 29. When the pawl 14' is returned to meshing engagement with the teeth of wheel 10, pawl 21 is removed from meshing engagement with the teeth of gear 17 whereupon spring 34 rotates the gear 17 counter-clockwise until the rods 33 engage the right end of the slots 29.

It will now be clear that selective engagement of the pawls 21 to 24 with their respective gears 17 to 20 by means of certain well known permutation bars will efiect difierent increments of movement to the rack 13 due to the difference in the lengths of the slots 29 to 32 in the gears 17 to 20, respectively. Any suitable mechanism such as linkages and permutation bars, well known in the art,

be used'to actuate the stop pawl 21 to efie'ct the smallest increment of spacing movement to be imparted to rack bar 13 whereasthe' depression of character keys such as the upper case M, W, etc. can be used to actuate thestop pawl 24- to efiect the largest increment of spacing to be impartedto the rack bar 13. I

It is thus observed that I have provided a simple, enicient, and relatively inexpensive mechanism to achieve the above mentioned objects wherein the depression of any selected key will cause the proper spacing to take placefor that particular width of character;

While I have described what 1 consider to be a hi hly desirable embodiment of my invention, it is obvious that many changes in form could be madewithout departing from the invention and I, therefore, do not limit myself to the exact form herein shown and described, nor to anything less than the Whole of my invention as hereinbefore set forth, and as hereinafter claimed.

What Iclaim is 1. In a mechanism of the class described, an escapement wheel loose on a shaft and tending to turn, a series of spacing gears rotatable on said shaft and having respectively concentric slots of different lengths therein, a connecting member fixed to the wheel and extending through said slots, a pawl associated with said wheel and stop pawls respectively associated with said gears, said 30 pawl and a selected one of the stop pawls being adapted to be operated to release the wheel and stop the selected gear to permit the escapement wheel to turn a determined distance. 7

2. The mechanism of claim 1 in which a spring on each gear is fixed at one end to the gear and at the other end to the connecting member.

3. In a mechanism of the class described, an escapement wheel loose on a shaft, a series of spacing gears rotatable on said Shaft adjacent said wheel, each of said gears having a concentric slot of a length difierent than those in the other gears, a rod fixed to the wheel and extending through said slots, said wheel being adapted to turn in a definite direction when released, an escapement pawl to normally engage said wheel to hold it, a stop pawl for each gear adapted to be moved into engagement with the teeth thereof, a spring on each gear fixed to the gear at one end and to the rod at the other and tending to hold the rod in one end of the siot in each gear, said escapement pawl being adapted to be released from the wheel, and a stop pawl adapted to simultaneously engage the teeth of its gear to permit the wheel to rotate until the rod engages the other end of the slot of the stopped gear.

Shepard Sept. 1, 1903 Worden May 25, 1920 

